Liquid-fuel-btjrning furnace



M. A. FESLER. LIQUID FUEL BURNING FURNACE, APPLICATION FILED NOV. u, I9l9.

1 ,376,0 1 O. Patented Apr. 26, 1921.

2 SHEETSfSHEET I.

M. A. FESLER. LIQUID FUEL BURNING FURNACE.

APPLICATION FILED NOVVII, 1919. 1,376,010.

Patented Apr. 26, 1921 UNITED STATES I PATENT OFFICE.

MILTON A. FESL'ER, OF OAKLAND, CALIFORNIA, ASSIGNOR TO PETROLEUM HEAT AND POWER COMPANY, A CORPORATION OF DELAWARE.

LIQUID-FUEL-BUENING FURNACE.

Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed November 11, 1919. Serial No. 337,177.

To all whom it may concern:

Be it known that I, MILTON A. FnsLnR, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented an Improvement in Liquid-Fuel-Burning Furnaces, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The invention to be hereinafter described relates to furnaces for burning fluid fuel, and more particularly to furnaces employing burners in which liquid fuel is atomized and injected through the furnace chamber.

One of the most important considerations in burning liquid fuel is the proper control of the air admitted into the furnace. A

minimum amount of air which will obtain complete combustion produces the best results. Slight variations in the air supply materially affect the combustion conditions, and therefore, it is desirable that the air supply shall be controlled with a desirable nicety of adjustment. One of the purposes of the present invention is to provide simple and efficient means for supplying air to the liquid fuel and for varying the supply of air according to conditions as required.

The liquid fuel is atomized and injected into the furnace under steam or air or other pressure necessarily with considerable force, in order properly to atomize the liquid fuel. This and the expansion of the gases of r combustion cause the burning gases to project through the furnace with a flame path of considerable length before combustion is complete. It is important that combustion shall be complete before the gases come in contact with the water tubes in the roof of the furnace. Otherwise the tubes will be excessively heated locally and injured. Heretofore, in the attempt to produce a long flame path before the gases come in contact with the water tubes, a burner has been introduced into the furnace adjacent the bridge wall so asto inject the liquid fuel toward the front wall of the furnace and toward the flaring or larger end of the furnace chamber. There are certain objections to this construction. Among others, the burner is located at a point remote from the front of the boiler where it is not conveniently accessible; the variations in the air supply are limited; and under normal conditions of operation, the fuel is injected into the furnace under such pressure that the gases will be sent toward the front wall of the furnace with so great force that they strike the water tube portions adjacent the front wall and are liable to burn out the same; and thus the gases are not properly distributed to the water tube portions at the roof of the furnace. Another purpose of the present invention is to introduce the burner into the furnace at the front wall thereof and preferably near the roof of the chamber, and to direct the gases of combustion down along the front wall of the chamber toward the base thereof, thence to the bridge wall, and upward to the water tubes at the roof of the chamber. As a consequence, the gases may have a long path of travel and combustion thereof may be co1nplete before impinging on the water tubes.

It is desirable to vary the supply of liquid fuel and heating effect for varying conditions depending upon the demand on the boiler. When a smaller supply of liquid fuel is being atomized and consumed, the steam pressure is reduced, and as aconsequence, the gases are not injected into the furnace with the force and length of flame ing to the force of injection of the fuel into the furnace. v

Vith the aforesaid and other purposes in View, the character of the invention may be best understood by reference to the following description of one good form thereof shown in the accompanying drawings, wherein V Figure '1 is a vertical section through a Babcock & Wilcox boiler having a furnace embodying the invention Fig. l is a section taken on line 1f-1 of Fig. l;

Fig. 1? on an enlarged scale is an end view of the burner;

Fig. 2 on an enlarged scale is. a vertical section taken on line 22 of Fig. 1; and

Fig. 3 is a front elevation of the lower portion ofthe front. of the boiler. Referring to the drawings, the boiler shown therein as equipped with a furnace embodying the invention, is of the Babcock & Wilcox type of well known construction, and comprises inclined water tubes 1 communicating with a front header 3 and a rear header 5 respectively communicating with the steam and water drum 7 through riser pipes 9 and down-flow pipes 11. Bafiles 13 and 15 are arranged transversely of the water tubes to cause the products of combustion to traverse the pipes several times in the course of their transit to the stack.

The furnace for the boiler, in the present instance, comprises a base 17, a bridge wall 19 at the rear end of the furnace, and a roof 21 extending from the bridge wall to the baflie 13.

A liquid fuel burner 23 may be provided of usual construction having oil and steam passages which deliver the oil and steam through a slit or orifice 25 at the under side of the delivery end of the burner, as will be noted in Figs. 1 and 2. The usual valves 27 and 29 are provided for controlling. the supply of oil and steam to the burner. The burner may be introduced into the front wall 31 of the furnace preferably adjacent the upper end of the furnace chamber. The construction is such that the atomized fuel is delivered from the orifice of the burner downward in fan-like form of curved cross section (Fig. 1*).

As stated, one of the purposes of the invention is to provide means for variably supplying air to the atomized oil as it is projected downward and rearward through the furnace chamber. This means, in the present instance of the invention, comprises a multiplicity of openings which may be conveniently formed of refractory brick checker work 33. The openings are graded and distributed in the direction of the path of the atomized fuel so as to provide a supply of air gradually increasing away from the burner.

To further supply air to the atomized fuel after it passes the checker work 33, a second group of openings 'may be rovided conveniently in the form of refi'actory brick checker work 35 beneath and formin a continuation of the checker work 33. The openings in the checker work 35 will also be graded and longitudinally distributed sees to increase the supply of air as the atomized fuel passes away from the burner. The checker work 33 and 35- may be supported by suitable means, in the present instance, in the form of bars 37. The checker work preferably should be gradually curved downward and rearward to deflect the ses of combustion toward the'base of the 0 amber. The graded and lon 'tudinally distributed openings thus afior ed will provide a supply of air. gradually increasing away from the burner and increasing the supply of air as the gases expand in their transit from the burner toward the bridge wall.

Suitable means may be provided for controlling the amount of air admitted through the openings in the checker work referred to. This means, in the present instance, comprises a damper door 39 which may be mounted on trunnions 41 (Fig. 3) journaled in bearings 43 mounted on the front wall of the boiler, the door being provided with a suitable handle 45. A similar door 47 may be provided beneath the door 39 and may have trunnions 49 journaled in bearings 51 mounted on the front wall of the boiler, said door being provided with ahandle 53. The door 39 communicates with a chamber 55 for admitting air to the checker work 33, and the door 47 communicates with a chamber 57 communicating with the checker work 35, the two chambers 55 and 57 being separated by a horizontal wall 59 of refractory brick. The construction is such thatthe doors may be swung to different positions of adjustment to vary the amount of air admitted through the chambers 55 and 57 to the openings in the checker workas required.

To provide for further variation in the heating effect, the combustion chamber may be provided with a plurality of burners, two being shown herein, each equipped with checker work and doors for controlling the supply of air admitted to the fuel. One of these burners or both may be operated according to the demands on the boiler.

To protect the burners from the gases of combustion curling back from the bridge wall, they may be provided with hoods 61 of refractory material supported by the front wall. 7

By my invention simple and efiicient means is provided for distribution of the air to the gases of combustion issuing from the burner and for varying the amount of air admitted according to conditions as desired. The air may be so controlled as to admit the minimum amount of air required to complete combustion before the ases reach the water tubes at the roofof t e combustion chamber. The transversely curved fan form of the gases of combustion produced by the curved orifice of the burner, desirably pockets the air admitted and tendsto confine the. same within the range of the gases of combustiomthereby further contributing to the efficiency of the. control.

The introduction of the burner into the combustion chamber ad' cent the front upper end thereof, and t e downward direction of the fuel from the burner, causes the gases of combustion to pass along the front wall toward the base of the combustion chamber up along the bridge wall and thence backward to the water tubes at the roof of said chamber. As a consequence,

the gases pass through the combustion chamher in a long flame path of sufficient length to insure complete combustion before reaching the water tubes. Thus, any possibility of localizing the flame on and'burning out of the water tubes are prevented.

A wide range of operation may be obtained by employing a plurality of burners with independent control of the burners, and independent control of the air admitted to the groups of checker work for the burners.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is 1. In a furnace for a water tube boiler, the combination of a combustion chamber having water tubes at the roof thereof and a bridge wall at the rear thereof, a liquid fuel burner projecting into the front of the chamber, brick checker work at the front of the chamber extending downward from the burner toward the base of the chamber and having openings therein graded and distributed in the direction of the flame from the burner, and means variably to admit air through the openings of said checker work to the fuel issuing from said burner.

2. In a furnace for burning liquid fuel, the combination of a combustion chamber, and a liquid fuel burner projecting through the front wall of said chamber adjacent the roof thereof and having an orifice for directing the fuel downward along the front wall toward the base of said chamber, said front wall being provided with openings graded and distributed longitudinally of the path of the fuel for admitting air thereto.

3. In a furnace for burning liquid fuel, the combination of a combustion chamber having a front wall, a base, a rear wall, and water tubes at the roof of the chamber, a liquid fuel burner having an orifice for directing the fuel downward along the front wall toward the base of said chamber, and means to supply a progressively increasing quantity of air to the fuel as it is injected along the front wall of said chamber.

4. In a furnace for burning liquid fuel, the combination of a combustion chamber, water tubes above said chamber, a liquid fuel burner entered through the front wall of said chamber, and having an orifice for directing the fuel downward along said front wall, a plurality of groups of openings for admitting air through the front wall to the fuel as it passes the same, and means independently to control the supply of air to said groups of openings.

5. In a furnace for. burning liquid fuel, the combination of a combustion chamber having a front Wall, a base and a rear wall,

water tubes above I said chamber, and a plurality of liquid fuel burners for injecting fuel downward along the front wall of said chamber toward the base thereof, the combustion chamber being provided with a wall having openings. graded and distributed along the path of the fuel to supply-a progressively increasing volume of air thereto.

v6. In a furnace for burning liquid fuel, the combination of a combustion chamber, a burner having a curved orifice for directing the fuel therefrom in arched fan form, and a wall for said chamber having openings therein disposed in fan form to deliver air into the fuel arch.

7 In a furnace, the combination with a combustion chamber, of a burner for delivering fuel into the chamber downward along the front wall thereof, said wall having a plurality of groups of openings for admitting air to the fuel to promote combustion thereof, and means to vary the amount of air admitted through said openings according to variations in the fuel supply.

8. In a furnace, the combination with a combustion chamber, of a burner for delivering fuel into said chamber, the latter having a wall provided with a plurality of groups of openings for admitting air to the fuel to promote combustion thereof, and means to admit air to one or more of said groups of openings according to the amount of fuel supplied by said burner.

9. In a furnace, the combination with a combustion chamber, of a burner for delivering fuel into said chamber, the latter having a plurality of groups of air admission openings progressively disposed in the bath of the flame from the burner, control means for varying the supply of air admitted to one of said groups of openings, and control means for varying the supply of air admitted to another of said roups of openings independently of said first named control means.

10. In a furnace for burning liquid fuel, the combination of a burner with a combustion chamber having an upright wall provided with upper and'lower zones containing openings to admit air to the fuel as it is injected from the burner along said wall, and means independently to regulate the amount of air admitted by said zones.

'11. In a furnace for burning liquid fuel, the combination of a burner with a combustion chamber having an upright wall provided with openings beneath the burner graded and distributed longitudinally to ad mit a progressively increasing quantity of air to the fuel as it passes from the burner along. said wall.

12. In a furnace, the combination of a combustion chamber having a front wall, a rear wall and a fiat base between said walls, a burner projecting through said front wall at a point remote from the base of the combustion chamber, said front wall having a multiplicity of distributed openings therein between the burner and the base for admitting air to the fuel as it is injected down past the multiplicity of distributed openings in the front wall, and said burner havingprovision for directing the fuel downward along the front wall past the openings therein. 10

In testimony whereof, I havesigned. my name to this specification.

MILTON A. FESLER. 

